Hesitation--a problem with ALL 6 cylinder engines?

Could be fouled plugs, or even bad leads. I've had that behaviour from both causes, as well as low-octane fuel. But first, check that the leads (plug *and* coil leads) aren't burnt at the ends. A bit of corrosion can cause all kinds of unpredictable behaviour too, so check all the main electric circuits for anything that might indicate intermittents or high resistance.

If you have to replace leads, consider spending a few $ extra for Magnecore leads or similar inductive *wire* leads. You'll never ever have to replace your leads again (*), and will always have a better spark.

(*) I had a Magnecore lead fail after 8 years once, and took it back to the dealer. He looked at me shamefacedly as he instantly repaired it, apologising profusely that the end hadn't been fitted correctly from the outset and it should never have happened. I was super impressed, needless to say :-).

That said, there are *many* things that can cause your symptoms. Hope you find it.

Clifford Heath.

There are a bunch of things that can cause hesitation or sluggishness.

Just as another example to add to what Clifford said, a bad Knock sensor will cause your ECU to dial back on the timing causing some major sluggishness. I have this happening to my car now, and it almost feels like it goes slower the harder I press the pedal.

Bill Bradley wrote:

My wifes '03 H6 OBW is glass smooth at all times and a pleasure to drive. heavier than my WRX for certain and a different type of drive - but no engine related issues - so far(no VDC). Did you get a CEL? Wonder what code it stored? When you floor it, did rpms go up but no movement? Maybe it's a transmission problem?

let us know what they find.

Carl

I've never experienced any hesitation in my 05 OBW with that engine.

I've had some hesitation problems on my 2000 OBW 2.5L H4. I've recently switched to higher octane gas, and it's smoothed out quite a bit. My hesitations normally occurred during stop-light starts from a standstill.

Yousuf Khan

Well, I had the Service Manager and several Tech's drive my car, they all felt the hesitation, but, they all said it was "normal for this engine". There is a firmware upgrade from May that is supposed to fix this, and, that had been applied, but, obviously didn't fix it.

I have an appointment with the Regional Rep next Wed, so, we'll see what he says.

I get the feeling that the AWD system probably puts an unusual amount of strain on these engines at certain RPMs, until they get to the meaty part of their torque curve. Subaru could really use a hybrid system, where a smooth electric motor does the initial motivation until the IC engine spools up.

Yousuf Khan

I have this problem with my 1997 Legacy GTB 2.0l Turbo... will take it to Subaru soon and see what they say...

This is a 4 cylinder car...

YKhan wrote:

The Regional Rep says that this is normal, too. I drove a few other 4 and 6 cylinder cars, both 2006 and 2007, and, they are all like this, although the

Yeah, well, that's upto you. I know one thing that I did notice when I was first test driving Subarus back when I first bought this thing, that the automatic felt quite "washed out" compared to the manual. So I ended up with the manual transmission. With the manual, I have control over the RPMs to get going at. I only suffer the hesitation if I'm not paying attention and let the RPMs get too low during start-off. And I have no problems with acceleration while already moving. Perhaps Subaru needs to pick a higher RPM for the automatic to start going too?

Yousuf Khan